Circuit controlling attachment for toy tracks



y 1950 M. H. FQlSBlE 2,515,209

CIRCUIT CONTROLLING ATTACHMENT FOR TOY TRACKS Y Filed July 27, 1949 jay.87 INVENTO? M W H. W

Patented July 18, 1950 CIRCUIT CONTROLLING ATTACHMENT FOR TOY TRACKSMarshall H. Frisbie, Hamden,-onn., assignor to The A. 0. GilbertCompany, New Haven, (301111., a corporation of Maryland Application July2'7, 1949,.Serial No. 107,049

Claims.

This invention relates to electric circuit controllersoperable whenattached to a toy railroad trackby the weight of a passing toy train.

One objectof the invention is to provide a circuit controller for thispurpose in the form of a simple compact unit of thin proportion whoseentire structuremay be borne by and beneath a fiexible'span of toy trackrails between the usual cross ties or sleepers that serve to hold therails in elevated relation to the underlying support surf-ace or roadbed.

Another object is to provide releasable fastening means to attach anddetach a unit of this kind readily at any desired location along thecourse of a conventional toy trackfor making its location variable.therealong at will.

Another object is to provide a circuit controller borne by atoy trackand whose relatively movable circuit controlling contacts are allcarried by a common rigid switch base so that they may all be raised andlowered .in unison with such base in the upward and downwardflexing of aresilient span of track caused by the weight of a passing toy train.

Another object is to construct the unitary switch base preferably as asingle body of insulative material thereby to do away with extrainsulators for spacing its electrically alive parts from each other orfrom the conductive rails of the track.

A further object is to enable the circuit controlling contacts tobelocated between, instead of laterallyaside-from, the :rails of thetrack.

Another object is to make possible minute and finely controlled manuallyadjustable variations of resilient resistance to the separation of onecircuit controlling contact fromanother circuit controlling contact andto the approach of one circuit controlling contact toward anothercircuit controlling contact.

Fig. 4 drawn on an enlarged scale is a side elevation of toy track railsbroken away to indicate Still another object is to enableall bindingposts for the connection of electric wires to the controller to becarried in fixed relation to one another on the common rigid structureof the switch base.

The foregoing and other objectives of the improvements will appear ingreater detail in the following description of a preferred embodiment ofthe invention .such description having reference to the appendeddrawings, wherein:

Fig. :lis a perspective view drawn on larger than full scale showing acircuit controller embodying the present improvements attached in placebe heath two track rails of which only fragments are shown.

Fig. 2 .is a plan View in preferred actual size showing the completecontroller unit of Fig. 1.

Fig.3 is a bottom plan View of the same unit showing an extended lengthof the track rails held separated by one-of the sleepers.

contraction of their length supported by sleepers and carrying theimproved circuit controller shown in section on the plane 4-4 in Fig. 2,looking in the direction of the arrows, the position of parts being aswhen the track is not loaded by weight of a passing train.

Fig. 5 is a side elevation of the structure in Fig. 4 showing thepositions assumed by the parts when the track rails are temporarilyflexed downward by the weight of toy rolling stock.

Fig. 6 is a view taken in section on the plane ii6 in Fig. 2 looking inthe direction of the arrows and is drawn on the same enlarged scale asFigs. 4 and 5.

Fig. 7 is an enlarged perspective view of parts of the assembledstructure shown in Fig. 1 with the tension adjusting nut broken away toexpose its point of pressure exerting engagement.

In the drawings a section of the length of a conventional toy railroadtrack is shown consisting of sli htly flexible resilient paralleltraction rails l2 and I3 supported at a fixed gauge of lateralseparation in a conventional manner on sleepers or crossties [4 whichare spaced sufficiently apart along the rails to permit both track railsto flex somewhat downward between the sleepers as indicated in Fig. 5.This occurs when the rails in unison receive the weight of rolling stockwheels [5 as the latter ride over or come to rest at the location of theimproved circuit controller.

The controller unit may have the following preferred construction. Theswitch base I8 is preferably an integral relatively rigid slab-like bodyof molded plastic or other insulative material shaped to provide acentral depending boss l9 containing a vertical bore at 28 and acounterbore at its top. This boss and bore afford guide bearing foranactuator 22 which is freely slidable up and down therein, herein chosenas illustrativeof any equivalent actuating medium so termed'in theclaims of this application. Within the broader aspects of the inventionactuator 22 may have sundry shapes and dispositions relative to switchbase [8 other than that herein shown. Actuator 22 is in the nature of aplunger whose head 23 occupies the counterbore 2i and whose bottom endhas riveted or otherwise fixed thereto a landing foot here shown as athin broad horizontal disc 24.

Somewhat above the top surface of switch base rivet 27 not only theanchored end of an electrically conductive spring leaf circuitcontrolling contact member 28 which extends diametrically acrosscounterbore 2i and overhangs head 23 of plunger 22 but also the anchoredend of a superimposed more flexible and resiliently weaker leaf spring25 most of whose length lies in somewhat vertically separated relationto contact member 28. Leaf spring 25 may be only about half thethickness of contact member 28 and its dipped formation 38 bearsdownward against member 28 for imparting variable auxiliary tensionthereto only at a single location in the latters length. Member 28carries and presents both upwardly and downwardly at its free endcontact point or points 29. This contact point is normally positioned asin Fig. 4 where it is shown to engage a stationary circuit terminal studor cooperative contact member 30 fixed on the base [8. In Fig. 5 contact29 is shown differently positioned to engage a higher circuit terminal3! which also is secured to base [8 on the recessed aligning seat 33 byrivet 32. The natural combined tendency of the self contained resiliencein member 28 and the self contained auxiliary resilience in leaf spring25 acts to maintain contacts 29 and 3B normally in mutual engagement.The rigidity of switch base It is relative in comparison with theflexibility of spring leaf 28 and has that meaning where used in theclaims hereof.

Leaf spring 25 is tensioned to adjustable degrees, and its resistance toflexing is thereby altered, by means of a super-imposed pressor nut 34having threaded engagement with a screw stud 35 which is fixedlyembedded in switch base l8. Nut 34 can conveniently be reached andturned by the operators fingers applied to its scalloped head or handleknob 36. The threaded length of stud 35 projects upward through freeclearanceapertures 31 in contact member 28 and I 48. in leaf spring 25.Preferably nut 34 does not bear directly on the broadside surface ofleaf spring 25 but instead bears on an upwardly embossed spot 39thereon.

By means of bus bars 40, 4| and 42 on the bottom face of switch base I6the flexible spring leaf contact member 28 and the stationary circuitterminals 30 and 3| are electrically connected respectively to bindingposts 43, 44 and 45, to which posts lead wires such as 46 and 4'! areattachable. This enables the make-and-break contact mechanism of theunit to be located between the track rails while its binding posts aredisplaced to a trackside location.

Switch base I3 is upwardly tongued at 49 to provide a horizontal groove50 in which a bottom or foot flange ll of rail 2! may b lodged removablyas best shown in Fig. 6. A bottom or foot flange ll of the other rail I3is correspondingly lodged beneath a fastening cam 5! that is pivotallyanchored by stud 52 to the switch base. The rail holding surfaces 53 and53 of cam 5! are cam shaped so as to press wedgingly against the baseflange and web of track rail I3 when the cam is swung clockwise in Figs.1 and 2. Because the crossties or sleepers l4 maintain the track railsspaced apart against lateral pressure of cam surface 53' toward theleft, such pressure forces the flang of rail [2 edgewise against thebevelled surface 54 of base lug 49 and at the same time cam surface 53wedges down against the bottom flange of rail l3, thus holding theswitch base l8 upward firmly against the bottom flanges of both rails.This quick means of attachment and detachment holds the switch baseremovably in fixed relation to the'rails at any chosen location in thecourse of the track.

The train operated action of the circuit controller is best,apparent'from Figs. 4 and 5. In

upwardly on spring leaf 23.

not rest lightly on thebed surface 13 which may comprise the top of atable, a floor carpet, or what not, representative of the road bed of arailroad. In Fig. 4 it is also apparent there is no tendency of theplunger head 23 to press- Hence contacts 29 and 36 remain normally inmutual engagement to complete a circuit from binding post 43 to bind--ing post 44. When the wheels l5 of toy rolling stock (not shown) passover the rails l2 and l3 directly above the switch base 18, the railstemporarily bow slightly downward between sleepers as indicated in Fig.5 causing the switch base it as a whole to sink to a lowered positionshown in Fig. 5.

In this, action of the switch base the plunger foot 24 is blockedagainst downward movement because it rests on or encounters the bedsurface I6. Hence th plunger head 23 cannot accom pany downward movementof contact member 28 and the latter is forced to flex upward by the nowimmovable plunger head so that carried contact point 29 is forced toleave engagement with contact 30 and may be caused to move upward farenough to engage overlying stationay contact 3| instead. Thus circuitcan be broken between binding posts 43 and 44 and circuit made betweenbinding posts 43 and 45, as a mere result of the arrival of rollingstock wheels in the position shown in Fig. 5. In this action neithersaid wheels nor any part of a toy train need be brought into contactwith any extraneous track or trackside object and the electric circuitgoverned by the improved controller does not pass through any wheel orother structure of the rolling stock.

When the circuit controller is installed as a unit at various chosenlocations along a course of track, variation may be encountered in thedegree of flexure of the tracks that will cause contacts 29, 30 to beopened. Also it may be desired to predetermine whether such deflectionshall or shall not operate to close contacts 29, 3!. The pressor nut 34is used for this and other adjustive purposes and may first be retractedupward on the screw thread of stud 35 until it is free from engagementwith leaf spring 25. After the switch base It has been securely anchoredto the track ,rails in its chosen location by the fastening action ofcam 5|, nut 34 may be set down to such degree of pressure against spot39 on leaf spring 25 that the resistance of the latter to forces tendingto flex contact member 23 upwardly can be predetermined and this willpredetermine what response member 23 will make to the downward thrust ofthe weight of the rolling stock on the track rails. Thus the circuitcontrolling response of the unit to a given track situation and to agiven weight of rolling stock can be varied for different desiredcircuit controlling results.

The appended claims are directed to and intended to cover not only theparticular embodiment of the invention illustrated and described hereinbut also all obvious or well-known variations of and equivalents for theshapes, sizes and relationship of parts coming within the broadestinterpretation of the language used in the claims.

I claim:

1. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separately by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base, and an actuating medium carried'by said switch base inoperative relation to at least one of said members and in movablerelation tosaid base projecting from the latter in position to beblocked against movement by the bed surface when said base is lowered bydownward deflection of said rails.

2. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad trackof the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which therails deflectresponsively to weight of said rolling stock, the combination of, aswitch base comprising an integral rigid body adapted to be carried bysaid rails in elevated relation to said bed surface, relatively movablecircuit controlling members on said switch base, and an actuating mediumcarried by said switch base in operative relation 'to at least one ofsaid members and in movable relation to said base projecting from thelatter in position to be blocked against movement by the bed surfacewhen said base is lowered by downward deflection of said rails.

3. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weightlof said rolling stock, the combination of, aswitch base comprising an integral rigid body of insulating materialadapted to be carried by said rails in elevated relation to said bedsurface, relatively movable circuit controlling members on said switchbase, and an actuating medium carried by said switch base in operativerelation to at least one of said members and in movable relation to saidbase projecting from the latter in position to be blocked againstmovement by the bed surface when said .base is lowered by downwarddeflection of said rails.

4. In an electric circuit controller tobe operated by the passing of toytrain rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on. a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base, and an actuating medium .carried by said switch base inoperative relation to at least one of said members and constrained torectilinear sliding movement relative to said base projecting from thelatter in position to be blocked against movement by the .bed surfacewhen said base is lowered by downward deflection of said rails.

5. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track. of the typecomprising resilient rails supported on and held sep arated by spacedsleepers adapted to rest on bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface, relatively movable ,circuit controlling members onsaid switch base, and a plunger slidable vertically through the saidswitchbase having a head end in operative relation to one of the saidcircuit controlling members and having a root end positioned to beblocked by the said bed surface against downward movement when the saidtrack rails deflect downward.

6. In an electric circuit controller to *be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base comprising an integral rigid body of insulating materialadapted to be carried by said rails in elevated relation to said bedsurface, relatively movable circuit controlling members on said switchbase, and a plunger slidable vertically through the said switch basehaving a head end in operative relation to one of the said circuitcontrolling members and having a foot end positioned to be blocked bythe said bed surface against downward movement when the said track railsdeflect downward.

7. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination or", aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base carried thereabove between said track. rails, and anactuating medium carried by said switch base in operative relation to atleast one of said members and in movable relation to said baseprojecting from the latter in position to be blocked against movement bythe bed surface when said base is lowered by downward deflection of saidrails.

8. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base comprising an integral rigid body of insulating materialadapted to be carried by said rails in elevated relation to said bedsurface, relatively movable circuit controlling members on said switchbase carried thereabove between said track rails, and an actuatingmedium carried by said switch base in operative relation to at least oneof said-members and in movable relation to said baseprojecting from thelatter in position to be blocked against movement by thebedrsuriace'when base is lowered by downward deflection of said rails.

9. In an electric circuit controller to be-operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base adapted to be carried bysaid rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base carried thereabove between said track rails, and a plungerslidable vertically through the said switch base having a head end inoperative relation to one of the said circuit controlling members andhaving a foot end positioned. to be blocked by the said bed surfaceagainstdownward movement when the said track rails Tdeflect "downward.

10. In an electric circuit controller to be operated by the passing oftoy train rolling stock I over a toy railroad track of the typecomprising resilient rails supported on and held separated by spacedsleepers adapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base including an elongated electrically conductive spring leafcarried on the top thereof, an actuating medium carried by said switchbase including a plunger slidable vertically through the latter having ahead end overhung by said spring leaf in a manner to operatively engagethe same, and having a foot end projecting from said base in position tobe blocked by said bed surface against downward movement when said baseis lowered by downward deflec- -tion of said rails.

11. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface,

relatively movable circuit controlling members on said switch baseincluding an elongated electrically conductive spring leaf carried onthe top thereof, an actuating medium carried by said switch baseincluding a plunger slidable Vertically through the latter having a headend overhung by said spring leaf in a manner to operatively engage thesame, and having a foot end projecting from said base in position to beblocked by said bed surface against downward movement when said base islowered by downward deflection of said rails, together with a device fortensioning said spring leaf including an adjustable resilient pressorelement bearing against said spring leaf in a broadside direction.

12. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward Which the rails deflectresponsively I to weight of said rolling stock, the combination of, a,switch base adapted to be carried by said rails in elevated relation tosaid bed surface,

relatively movable circuit controlling members on said switch baseincluding an elongated electrically conductive spring leaf carried onthe top thereof, an actuating medium carried by said switch baseincluding a plunger slidable vertically through the latter having a,head end overhung by said spring leaf in a manner to operatively engagethe same, and having a foot end projecting from said base in position tobe blocked by said bed surface against downward movement when said baseis lowered by downward deflection of said rails, together with a devicefor tensioning said spring leaf including an adjustable resilientpressor element bearing against said spring leaf in a broadsidedirection,

and a screw threaded member cooperative with said resilient pressorelement in a manner to flex the same. I

13. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base adapted to be'carried by said rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base including an elongated electrically conductive spring leafcarried on the top thereof, an actuating medium carried by said switchbase including a, plunger slidable vertically through the latter havinga head end overhung by said spring leaf in a manner to operativelyengage the same, and having a foot end projecting from said base inposition to be blocked by said bed surface against downward movementwhen said base is lowered by downward deflection of said rails, togetherwith a device for tensioning said spring leaf including an adjustableresilient pressor element comprising a leaf spring substantially thinnerthan said spring leaf and bearing thereagainst at a single location inthe flexible length of said spring leaf.

14. In. an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination of, aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base including an elongated electrically conductive spring leafcarried on the top thereof, an actuating medium carried by said switchbase including a, plunger slidable vertically through the latter havinga head end overhung by said spring leaf in a manner to operativelyengage the same, and having a foot end projecting from said base inposition to be blocked by said bed surface against downward movementwhen said base is lowered by downward deflection of said rails, togetherwith a device for tensioning said spring leaf including an adjustableresilient pressor element comprising a leaf spring substantially thinnerthan said spring leaf and bearing thereagainst at a single location inthe flexible length of said spring leaf, said tensioning device alsoincluding a screw threaded member cooperative with said leaf spring in amanner to flex the same.

15. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to Weight of said rolling stock, the combination of, aswitch base adapted to be carried by said rails in elevated relation tosaid bed surface, relatively movable circuit controlling members on saidswitch base carried thereabove between said track rails, and anactuating medium carried by said switch base in operative relation to atleast one of said members and in movable relation to said baseprojecting from the latter in position to be blocked against movement bythe bed surface when said base is lowered by downward deflection of saidrails, together with binding posts carried by said switch base in alocation aside from the said track, and bus bars mounted on the bottomof said switch base extending crosswise one of the said rails from thesaid circuit controlling contacts to said binding posts respectively.

16. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination with saidrails and sleepers of, a switch base adapted to be carried by said railsin elevated relation to said bed surface, relatively movable circuitcontrolling members on said switch base, and an actuating medium carriedby said switch base in operative relation to at least one of saidmembers and in movable relation to said base projecting from the latterin position to be blocked against movement by the bed surface when saidbase is lowered by downward deflection of said rails, said sleepersbeing spaced sufficiently far apart along said rails to enable thelatter to deflect temporarily downward and carry said switch basetherewith into closer proximity to said bed surface responsively to theweight of toy rolling stock borne by said rails between said sleepers.

17. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination withbottom laterally projecting foot flanges of said rails of, a switch baseadapted to be carried by said rails in elevated relation to said bedsurface, a rigid anchorage tongue on said switch base in raised relationto the top surface thereof retainingly overhanging the foot flange ofone of said rails, clamping means operative to hold the last said footflange under said anchorage tongue, relatively movable circuitcontrolling members on said switch base, and an actuating medium carriedby said switch base in operative relation to at least one of saidmembers and in movable relation to said base projecting from the latterin position to be blocked against movement by the bed surface when saidbase is lowered by downward deflection of said rails.

18. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination withbottom laterally projecting foot flanges of said rails of, a switch baseadapted to be carried by said rails in elevated relation to said bedsurface, a rigid anchorage tongue on said switch base having an obliquewedging surface rising fixedly from the top surface of said switch baseand overhanging the foot flange of one of said rails, a. wedging devicecarried movably by said switch base in position to engage the track in amanner to thrust the last said rail flange laterally against saidoblique camming surface of said anchorage tongue, relatively movablecircuit controlling members on said switch base, and an actuating mediumcarried by said switch base in operative relation to at least one ofsaid members and in movable relation to said base projecting from thelatter in position to be blocked against movement by the bed surfacewhen said base is lowered by downward deflection of said rails.

19. In an electtric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination withupright webs and bottom laterally projecting foot flanges of said railsof, a switch base adapted to be carried by said rails in elevatedrelation to said bed surface, a rigid anchorage tongue on said switchbase in fixed raised relation to the top surface thereof retaininglyoverhanging the foot flange of a first one of said track rails, a rotarycam having plural camming surfaces eccentrically pivoted on and abovethe top surface of said switch base in position to overlie the footflange of a second one of said track rails, one of said camming surfacesbeing disposed to thrust laterally against the upright web of saidsecond one of said rails in a direction to maintain said flange of saidfirst one of said rails under said tongue and the other of said cammingsurfaces being disposed to overlie and thrust downward on said footflange of said second one of said rails, relatively movable circuitcontrolling members on said switch base, and an actuating medium carriedby said switch base in operative relation to at least one of saidmembers and in movable relation to said base projecting from the latterin position to be blocked against movement by the bed surface when saidbase is lowered by downward deflection of said rails.

20. In an electric circuit controller to be operated by the passing oftoy train rolling stock over a toy railroad track of the type comprisingresilient rails supported on and held separated by spaced sleepersadapted to rest on a bed surface toward which the rails deflectresponsively to weight of said rolling stock, the combination withupright webs and bottom laterally projecting foot flanges of said railsof, a switch base adapted to be carried by said rails in elevatedrelation to said bed surface, a rigid anchorage tongue on the saidswitch base having an oblique wedging surface risin from the top surfaceof said switch base and overhanging the foot flange of one of saidrails, and a rotary cam eccentrically pivoted on and above the topsurface of said switch base in position to overhang the foot flange ofanother of said rails and thrust laterally against the upright web ofone of the last said rails in a direction to force said rail flangeagainst said oblique wedging surface of said tongue thereby to draw andmaintain said switch base firmly against the bottom of the foot flangeof the first said rail, relatively movable circuit controllin members onsaid switch base, and an actuating medium carried by said switch base inoperative relation to at least one of said members and in movablerelation to said base projecting from the latter in position to beblocked against movement by the bed surface when said base is lowered bydownward deflection of said rails.

MARSHALL I-I. FRISBIE.

No references cited.

